Neural stimulation has been proposed as a therapy to treat high blood pressure. For example, it has been proposed that electrical stimulation can be used to reduce blood pressure when the electrical stimulation is directed at the baroreceptor regions to induce a baroreflex response. Baroreceptors play an important role in regulating blood pressure, and are located throughout the body, but primarily in the arch of the aorta and the carotid sinuses of the left and right internal carotid arteries. Through a negative feedback baroreflex system, the central nervous system can regulate the BP to maintain the blood pressure at a relatively stable level. For example, arterial pressure that causes stretch triggers the baroreflex to send nerve impulses to the brain which responds by controlling the pumping activity of the heart and blood vessel dilation to reduce the blood pressure.
The blood pressure response can fluctuate dramatically when different areas of the baroreceptor region are stimulated. For example, the blood pressure response at a first site within the baroreceptor region can be significantly different than the blood pressure response at a second site within the baroreceptor region. Animal experiments indicate responses can dramatically fluctuate spatially within 1 mm. Experience with humans also show focal distribution. Thus, the implantation of a baromodulation device to stimulate a small baroreceptor region in the carotid sinus usually requires extensive mapping of the internal carotid arteries in order to find a desirable stimulation location along the carotid artery that provides an effective or an apparently most effective control of blood pressure. Currently, surgeons manually hold one or more electrode(s) at various locations near the carotid sinus to map the baroreceptor region during an implantation procedure. Mapping may take up to several hours. This procedure takes significant time and effort due to the difficulty of manually positioning the electrode and maintaining steady and consistent blood pressure. Longer procedure times also undesirably expose the patient to longer anesthesia times. Thus, the clinical procedure is often unable to access a full mapping area. Moreover, the manual operation may cause trauma, or introduce mechanical activation of the baroreceptors which may hinder the evaluation of the blood pressure responses to the electrical stimulation.